So much great info has been posted already about this. Start by removing the carb pack, which is not all that easy but doable. I remove the throttle cables from the grip end first to allow enough slack at the carbs. That makes removing the cables from the carbs a lot easier. It helps to loosen the air box and slide it back as far as you can. I do not remove the spigots from the head but some people do. Once all the clamps are loose I use a long bar to pry them back from the spigots. (be careful how you exert pressure and where) So far, so good. I will recommend doing one at a time and not removing them from the "runner" bar that they are attached to. Invert and remove a bowl. Remove jets and clean. The wire size for the slow jet is .0011" (eleven ten thousandth of an inch) The jet is the smallest and most often clogged. It affects drivability and off-idle throttle response. I use Berkbile 2+2 for a carb cleaner (not available in some states) Wiring out the slow jet is the only way to ensure the jet is actually open and the right size. No, I don't recommend removing the diaphram / slides. First off, if you had a bad one, you'd know it. Real flat acceleration and poor (very) poor performance. If you stick a finger into the intake side bore and lift a slide up and let it fall, they make a very distinct noise. As in whoosh... No noise, bad slide. Try it and see. If you remove them you run the chance of the diaphram "growing" and not getting it back into place. This is caused by the wonderful fuel we have and it's effect on that material. Once released from the caps and exposed to air, all bets are off. It's happened too often in our shop. Same thing happens to the bowl gaskets (O ring) . Leave 'em in place or buy new. "Back in the day", we removed and inspected all these parts... no longer. But, that's when gas was gas and men were men. You can reduce the clearance where the actuator contacts the accellerator pump arm if you want to. I use a silicone spray on the spigots to allow the carbs to slip back in when you're done. Liquid soap works just as well. I do recommend a carb sync after major work like this. For what it's worth, I hope this helps. Maybe just use Seafoam ?
--- On Tue, 4/28/09, tharrisn <[email protected]> wrote: From: tharrisn <[email protected]> Subject: [Nighthawk Lovers] Re: NOISE cont. To: "Nighthawk Motorcycle Lovers!" <[email protected]> Date: Tuesday, April 28, 2009, 8:36 AM I found some caps for the anti-foam chambers and have ordered them. Should know shortly if they're available. They weren't too expensive and got a bunch of new o-rings for the oil pipes too. Only found one of the eight a little marginal but the manual said replace 'em all. If the place I ordered the caps can't get 'em I'll go the sealant route. Everything else looked good. No pitting, holes or scarring on the cam lobes or bearing surfaces. Before putting the bearing caps back on I smeared a very light coat of moly grease on the lobe and bearing surfaces. While I have everything kinda apart (I didn't have to remove the camshafts totally to get to the hydraulic adjusters) I figured I might as well work over the carbs too. Can you point me to a good resource for rebuilding the carbs? I think I read you don't recommend removing the diaphragms and to use some appropriately sized piano wire to insure the jets are clean. Along with the other parts I've ordered new o-rings for the carb to cylinder junction. Sure would like to use Viton o-rings as replacements but it's REALLY hard to find stuff like this locally. On Apr 28, 12:05 am, Dennis Hammerl <[email protected]> wrote: > OK, not too bad on your part. I'm a little foggy with some of your terminology but I think I get it. Yes, you can reseal the anti-foam chambers with a good silicone seal. Allow 24 hours before starting the engine. I always fill them with oil before re-assembly. With the silicone that may be a problem. Oil and silicone don't get along before the silicone sets up. At least put some in and clean the gasket surface with alcohol before the silicone is applied. How did the cam lobes look ? No scaring ? holes, pits ? > > --- On Mon, 4/27/09, tharrisn <[email protected]> wrote: > From: tharrisn <[email protected]> > Subject: [Nighthawk Lovers] Re: NOISE cont. > To: "Nighthawk Motorcycle Lovers!" <[email protected]> > Date: Monday, April 27, 2009, 9:14 AM > > Dennis, > > Update to the '83 CB650SC Nighthawk hydraulic valve adjuster > "tapping" > saga. It's been awhile since my last post but it's taken awhile to > collect this information...besides the weather has turned nice and I > was riding the thing. <grin> > > I added Marvel Mystery Oil and then put several hundred miles on the > bike results: > > - The intermittent clatter cleared up initially but now is pretty much > all the time > - With stethoscope isolated trouble to cylinder(s) 1 and/or 2 intake > valves > > Since the clatter is all the time now that was a good sign for me > (makes it easier to diagnose). Anyway, decided to pull the cam cover > off and take a peek. Found a couple things. > > - oil hole caps on intake and exhaust 1 and 2 cylinders in poor shape > - inspection and bleeding of all tappets revealed six of the sixteen > somewhat marginal > - visual inspection of everything else looks good > > The oil hole cap on the intake was even out of place a bit leaving the > oil pocket open. (Of course the cap could have been dislodged when I > took the cam cover off but none of the others were. Anyway, the rubber > lips on both caps were cracked and broken in several spots. The intake > again was the worst. > > Aha, says I. Since this oil pocket is supposed to keep the oil to the > adjusters from filling with air bubbles maybe this oil pocket cap > isn't doing its job? > > Replacing the hydraulic adjusters was going a little overboard since > they really weren't too bad. I had some spares that tested a bit > better so installed them just for grins. > > Ok, question...does anyone on this list have some spare oil pocket > caps? Do I need to replace these bad caps or maybe a good silicone > sealant will inject new life into the existing caps by sealing them on > the oil pockets? What do you think Dennis? > > Thanks for all the help. This project is turning out to be kinda fun. > > On Mar 16, 12:58 am, Dennis Hammerl <[email protected]> wrote:> Good thought, however you used Sea Foam. That should have cleaned that up > > if it works like they say it does. Do the MMO, I know what that does. At least > it will shift better. > > > --- On Mon, 3/16/09, tharrisn <[email protected]> wrote: > > From: tharrisn <[email protected]> > > Subject: [Nighthawk Lovers] Re: NOISE cont. > > To: "Nighthawk Motorcycle Lovers!" > > <[email protected]>> Date: Monday, March 16, 2009, 12:26 AM > > > What if there was a little varnish or other debris on the check valve in > > the tappet. The varnish would allow the tappet to function "normally" > when fed pressurized oil but would "leak down" fairly easy thus > creating the clatter after a hot start. Just conjecture but interesting to think > about. On Mar 15, 9:41 pm, Dennis Hammerl <[email protected]> wrote:> If the adjuster had failed, no amount of oil pressure would make it SHUT > > UP. If yours quiets down some times, what do you think ? > > --- On Sun,3/15/09, tharrisn <[email protected]> wrote: > From: tharrisn > > <[email protected]> > Subject: [Nighthawk Lovers] Re: NOISE cont. > > To: "Nighthawk Motorcycle Lovers!" > <[email protected]> > Date: Sunday, March 15, 2009, > 9:08 PM > > Ok, it's get the oil pressure checked first. > > > It's gonna take me a bit to get back to this project. I'm helping > > escort a group of teenagers on a back packing trip. Should be fun...I > think > I'm the token old> guy? <grin> > > On Mar 14, 11:33 pm, Dennis Hammerl > <[email protected]> wrote:> A great question. Before we get into that, > > I would call your attention to > > the location of the oil pressure > sending unit and the fact that the upper end > (cams, etc) are the last to > get oil. That's why I'm so aghast at gonzo > RPM starts. With that in > mind, it's not too difficult to see that the light > can go off (oil > pressure good) long before the critical upper end parts get > lube. Many > years ago we would start a cold CB450 in the garage with no radio > on and > the door closed. At exactly 58 seconds after start-up, it would suddenly > > get very quiet. It took that long to oil the upper end ! Lets not speculate on> any damage without a real pressure check first. I know that going anywhere > > near > a dealer is like being condemned to hell, but suck it up and take this > variable > out of the equation. In the end you may have to remove the head > cover just to > examine> the problem. Not yet. > > > --- On Sat, 3/14/09, tharrisn > <[email protected]> wrote: > > From: tharrisn > > <[email protected]> > > Subject: [Nighthawk Lovers] Re: NOISE cont.> > To: "Nighthawk Motorcycle Lovers!" > > > > <[email protected]>> Date: Saturday, March 14, 2009, > 11:02 PM > > > Would low oil pressure cause other noticeable problems > besides the > > tappet noise? > > > I know "idiot" > lights on cars are notoriously bad at indicating > > problems but what > about our bikes? I ask because the light comes on as > > it should when > turning the ignition on but promptly goes off when the > > engine starts.> > > On Mar 14, 2:06 pm, Dennis Hammerl <[email protected]> > > wrote:> > > This is starting to sound like > > > an oil pressure leakback, caused by #1 thin oil (from heat) or that #2 > > the Sea Foam has loosened up some grunge that is unable to escape from that part of the system since a I described, is not open-ended. Now on the #1 cause, I'd get a dealer to check its real oil pressure when hot. There is a screw in gauge that dealers have to do this. > > Shouldn't cost much to check. Low oil pressure can be many things. Don't panic. Since you didn't use anything on the second oil change we can't accuse anything of diluting the oil. > > > > > > --- On Sat, 3/14/09, tharrisn > <[email protected]> wrote: > > > From: tharrisn > > <[email protected]> > > > Subject: [Nighthawk Lovers] Re: NOISE > cont. > > > To: "Nighthawk Motorcycle Lovers!" > > > > <[email protected]>> Date: Saturday, March 14, > > 2009, 11:17 AM > > > > Doesn't sound like all the tappets are > noisy but a few and not > all the > > > time. They are the loudest > after the bike is> hot and sets for ten minutes > or so. > > I can almost > > guarantee when I start it back up and take off the noise will > be > > > very pronounced until it eventually quiets back down after a mile or two >> (quicker if I rev it a bit). They'll stay quiet until it idles for > > > some time > > or I shut if off and start it again while still hot. > I've changed > oil and > > filter twice now in 800 miles. The > first change I added SeaFoam (1/3 can). > > Second change straight engine > oil (Shell 5W-40 Rotella-T). I'll make > the > > next change using > Marvel Mystery Oil. I've never used MM Oil before. > How > > much > can I safely put in the engine of this 83 650, or just follow > directions on> > can? Will it hurt anything if I continue to "soup up" the > > engine oil > > at each change with MM Oil no matter how long it takes > > to stop the tappet > noise? > > If I change oil at say 300 to 500 > miles the next several> times do > > I need to change the oil filter> too or can I skip to every > > > > > other change while > > working on this problem? I'm going to give the > engine > > every > opportunity to purge it's little gremlins before taking more > drastic> > measures like pulling the cylinder head cover. But, I'm collecting > > some > > spare parts should I need to dig deeper. You have helped a > > bunch! Thank > you. > > On Mar 13, 10:42 pm, Dennis Hammerl<[email protected]> wrote: > > I > > guess I stirred > > something up. I did check parts sites and found no new > parts > > > available. (that puzzles me, I never used any) They don't wear out and > > you > > can purge them. There is a tool for purging the air that you > don't > need, > > just makes it easier. Let's start here; do > they (one or more) tap all > the > > time, some of the time, once in > awhile ? For the always and often cases, > you may > > have to remove > and purge. For the once in awhile, CHANGE OIL... then > change it > > > again. Get the nasties out. The> 3K RPM deal is to force out the> > > particle. In practice, > > consider the adjuster like an oil pressure gauge. > > > > > > It's a dead-end that reacts to pressure. They do leak some out of the > > bore > > and back into circulation. I change my oil every thousand miles. > Comes out > like > > it went in. Seems a shame but the alternative > would be more so. My one > 700s > > started to tap on a trip and > without any option, I continued to ride it > home. It > > stopped some > miles later and I changed the oil next day. > Never > heard from >> again. Any top-end work and I remove them and place right-side up till I > > > reinstall. Somebody once tipped over a few and I had to purge them > > before > > replacing in motor. If the problem persists and needs > attention, the > offending > > ones are easy to identify. To save time, > use a screwdriver as a > stethoscope and > > get a good idea of > it's general location. There should be no clearance > at > > any > valve. Since > > > they retain oil, the ones that are really hard to push > down are > > > good. > > ... > > read more » --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Nighthawk Motorcycle Lovers!" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nighthawk_lovers?hl=en -~----------~----~----~----~------~----~------~--~---
